The present invention relates to communications systems and, in particular, to an improved system for improving voice quality in a telephony over LAN (ToL) system.
Internet Protocol (IP) telephony and Telephony over LAN (ToL) systems allow voice or other media to be transported over the same network as user data. Such systems typically attempt to establish voice connections of the highest quality the network will support. For example, certain systems negotiate a “highest quality” codec or other setting during call establishment. Still other systems have preconfigured codec settings of relatively high quality.
Once a call is connected, the voice quality can deteriorate if the network gets clogged with other user data, such as multiple large print jobs or large file transfers. Because load on the network can be highly variable, both in terms of volume and type of data, it can be difficult to anticipate deterioration in voice quality and thus select an appropriate voice quality setting. Commonly-assigned U.S. patent application Ser. No. 09/668,038 filed Sep. 21, 2000, titled SYSTEM AND METHOD FOR TROUBLESHOOTING TOL SYSTEM VOICE QUALITY, which is hereby incorporated by reference in its entirety as if fully set forth herein, describes a system for reporting network or voice quality problems identified by a user during the course of a call. While such reporting may enhance a system administrator's ability to configure future settings, it does not necessarily help with an ongoing call.
Certain systems allow a user to change system settings by parsing through sets of menu options. The typical user, however, is not necessarily sophisticated enough to be able to make a desired change. For example, the average telephone user probably does not know the difference between a G.723 and a G.729 codec.
Some cordless telephone systems allow a user to change a channel between handset and base station by pushing a button during the course of a call. Other than being on substantially adjacent frequency bands, each channel is essentially the same in terms of voice quality settings and the choice is essentially random. Such trial and error systems have met with only moderate success.
As such, there is a need for an IP telephony system that allows a user to continue a call even while other network activity causes a deterioration in voice quality. There is a further need for an IP telephony system that allows a user to change voice quality settings during a call.